Plan b

So on April 9th I took plan b and I don't plan on ever having unprotected sex again. About a week and a couple days later I started spotting, on April 17th. it lasted till this Tuesday. Then it stopped for Wednesday. Then today I started cramping like when I get my period and started bleeding again. But a little heavier. My period isn't due till April 29th. Could it be my period or just still spotting...? Please I'm so confused and I've been researching, and none of it is helping.